Electric-lighting system



(No Model.)

ELECTRIC LIGHTING SYSTEM. No. 400,214. Patented Mar. 26, 1889.

s (a '7% i MM srfiysffi'm 0/ llh'd l kfi l N. PEIERS. Pholo-Litlwgnphar, Washinglnn. ac

IVILLIAM L. HORNE, OF MERIDEN, ASSIGNOR TO rrrcn.

TIIE HORNE VACUUM COMPANY, OF HARTFORD, CONNEOTIGUT.

ELECTRIC-LIGHTING SYSTEM.

SPECIFICATION forming part of Letters Patent No. 400,214, dated March 26, 1889.

Application filed October 28, 1887. Serial No. 253,639. (No model.)

To aZZ whom it may concern.-

lie it known that 1, WILLIAM L. HORNE, a citizen of the United States, residing at Meriden, in the county of New Haven and State of Connecticut, have invented certain new anduseful Improvements in Electric-Lighting Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My present invention relates to the art of electric lighting, and more particularly to electric lighting by means of what are known as arc lamps.

It consists in certain means for accomplishing desirable results, and especially in means whereby the life of the carbons is indefinitely prolonged and a greater amount of illuminat ing-power is secured for the expenditure of the same amount of electrical energy.

In the accompanying drawings I have shown one mode in which I have contemplated employing my invention, and have fully disclosed said invention in the following description and claims.

In the drawings, Figure l is a perspective view of a lamp and its inclosing-case. Fig. 2 is a section of the bottom plate of the lampcase. Fig. 3 is a view of a portion of asystem or plant arranged in accordance with my invention. Fig. 4: is a diagram of a single plant of three lamps.

It is well known that the carbons of arc lamps are rapidly decomposed when burning in the open air, necessitating the supply of each lamp with fresh carbons at short intervals. This is a great expense to the companies furnishing the light, not only for the carbons themselves, but also for the wages of the men required to effect the change. The constant dropping of heated particles from the decomposing carbons is also a frequent source of accidents by fire, and precludes the use of this means for lighting in places where the light would otherwise be desirable. I avoid these objectionable results by placing the lamp in a glass case and forming therein a total or partial vacuum, as may be found most efficient. As the electric current will pass more readily from one carbon to another in vacuum than in open air, I am enabled by this means to elongate the arc and thereby increase the illuminating-power of the lamp.

In the construction shown in the drawings the lamp is provided with an inclosing-case consisting of an inclosing-cylinder of glass, A, fitted at top and bottom into metallic caps to a. The cylinder is connected to the caps by an air-tight joint, and the caps are provided with suitable means whereby the carbons can be inserted or removed when desired.

In Fig. 2 I have shown the cap ct provided with a screw-plug, of, which serves as a holder for the lower carbon; but the lower carbon may be held by a part of the lamp, as usual. The cap a may be provided with a similar plug fitting an aperture therein sufficiently large and so located as to permit the insertion and removal of the upper carbons. The feeding mechanism is located in the case and the electr al connections may be made through the plugs or through the caps or through the upper cap alone, as may be preferred. In some cases I may make the casing inclosing the regulating mechanism of the lamp air-tight and make the same the top cap of the inclosing-case. I have also contemplated forming a case by dispensing with the lower cap and making the bottom of the case entirely of glass, and preferably integral with the cylindrical portion. A source of obstruction to the rays of light beneath the lamp is thereby avoided.

I prefer to exhaust the air from the lamp-case (I I 8 5.

by means of an air-exhausting device located at the central station of aplant and connected to the lamps by means of a system of pipes similar to that used in gas lighting, but smaller. These pipes may be placed in the ground or carried on the poles erected for the light-conductors. In Fig. 3 Ihave shown part of such a system in which the air-exhaust pipes are located partly underground and partly upon the conductor-supports; and in Fig. a I have shown in a diagrammatic way a complete plant of three lamps. In these figures, S is the central station, 3 the electric generator, and s the exhausting device located at the central station. A A A are the lamps; I) b, the electric conductors;

O, the main air- I06 exhausting pipe, and toe the pipes connecting the lamp-cases with the pipe C. Each of? the pipes c c c is provided with a cut-off cock near the lamp. In each of the lampcascs I employ a valve, e, of peculiar construction. This valve is suspended above the open end I of pipe 0 by a sensitive spring. This spring l is of such strength as to just maintain the l valve in the position shown and permit the air to be exhausted slowly and gradually from the lamp-case; but on. the sudden i nflux of air to the lamp, caused by breaking the case or other accident, the spring will. in'n'nediately yield and cause the valve to close pipe 0. I In my systenithefeedingmechanism is conl structed to maintain an are of a length corresponding to the degree of exhaustion within the case. The carbons will be decomposed very slowly and will lasta long time without change. \Vhen it becomes necessary to replace the carbons in a lamp, the cock near the lamp is turned so as to cut off communication with the main air-exhaust pipe. The carbons are then changed, the lamp sealed, and the cock opened. This adds to the pipe system of circulation only the air in the lamps in which the carbons are changed. Asufficient time before the hour for lighting the lamps the air-exhausting mechanism is put in operation and the air withdrawn from the various main pipes and lan1pcases until the desired degree of rarefaetion is obtained. The lamps are then lighted and the exhaust continned at such speed and to such extent as to maintain the proper degree of exhaust and removing all air entering the system by reason of leakage, and all, gases generated in the lamps. I may prefer to employ two exhaust mechanisms of d'ilterentcapacities-the larger to be employed in exhausting the air in the first instance and the smaller to be used where it is only desired to maintain the degree of exhaustion attaim'ad and remove the gas.

I do not desire to be limited to my exact constructions, as they may be greatly varied without departing from ihe spirit of my invention.

\Vhat I claim, and desire to ters Patent, is

1. A case for inelosing an arc lamp, provided with an aperture at the top for the re moval of the upper carbon, a closure for the same, and aperture, at the bottom for the removal of the lower carbon, and a closing-plug for said aperture, provided with a socket for receiving and holding the lower carbon in proper position, substantially as described.

2. An airtight inclosing-case for an arc lamp, an exhaust-pipe openinginto and communieating with said case, and a valve above the opening within the case, substantially as described.

In testimony whereof I afiix my signature in presence of two witnesses.

\V M. L. l [(IRNE.

secure by Let- \Vitnesses:

L. P. WHITAKER, E. 'l. WALKER. 

